The only time it's an issue is when I have to tell a client what they've provided me won't work as is and they get upset. Any time a client exclaims their [insert person with no professional experience...

You might want to pre-sell your offerings to see what kind of market you have before signing a contract on dedicated hosting of any sort. Also you might also want to find out if you can setup some kind of software to throttle the max amountof bandwidth each user can use, if you don't somebody will come a long with a huge pipe and grind your service to a halt. Is that a terabyte per month? That equals out to be a constant 3mbit stream (2 T1's) and 20 or 30 hi-speed users would max that out.

Personally I have no need for video hosting, but some others might tell you, but you might want to make it a per byte thing rather than a flat fee, in case a video gets linked a lot of places and sucks your bandwidth away.

We had several 'free' download graphics sites which we ended up turning into subscription sites to help offset the badwidth costs and it worked out rather nicely.